EarthRef.org Reference Database (ERR) -- Bloxham 2002

Using a numerical dynamo model, we examine whether quasi-stationary high latitude flux bundles which are observed in the geomagnetic field over the last 300 years, and possibly over much longer time periods, result from thermal core-mantle interactions. We do so by imposing lateral heat flux variations at the core-mantle boundary based upon the dominant pattern of seismic heterogeneity in the lowermost mantle. We find that the time-averaged field then has a similar arrangement of flux bundles to that observed during the last few hundred years. However, the field is time-dependent, and this arrangement of flux bundles is not a feature of the field at all times. Using a numerical dynamo model, we examine whether quasi-stationary high latitude flux bundles which are observed in the geomagnetic field over the last 300 years, and possibly over much longer time periods, result from thermal core-mantle interactions. We do so by imposing lateral heat flux variations at the core-mantle boundary based upon the dominant pattern of seismic heterogeneity in the lowermost mantle. We find that the time-averaged field then has a similar arrangement of flux bundles to that observed during the last few hundred years. However, the field is time-dependent, and this arrangement of flux bundles is not a feature of the field at all times.